Event detecting device including an event signal generator and an output signal generator

ABSTRACT

An event detecting device may include an event signal generator configured to output a plurality of event signals, each including a first data and a second data having mutually complementary attributes and respective address data indicating positions of pixels having output the first data and the second data, a data manager configured to store one of the first data and the second data of a first one of the plurality of event signals and the respective address data in a buffer as first sub data when only one of the first data and the second data of the first one of the plurality of event signals includes the event information, and an output signal generator configured to generate an output signal using the first sub data and a second sub data when the second sub data, different from the first sub data, is stored in the buffer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to Korean PatentApplication No. 10-2017-0029687 filed on Mar. 8, 2017 in the KoreanIntellectual Property Office, and to Korean Patent Application No.10-2017-0150602 filed on Nov. 13, 2017 in the Korean IntellectualProperty Office, the entire contents of which are hereby incorporatedherein by reference in their entirety.

BACKGROUND

Embodiments of the inventive concepts relate to electronic devices, andmore particularly, to event detecting devices.

Event detecting devices are devices that are configured to detect theoccurrence of events by detecting a visual change, and may be applied tovarious fields such as autonomous vehicles, artificial intelligence, andthe like. When event detecting devices detect a significant change bysensing light, the event detecting devices may convert the detectedchange into electrical signals and may output the converted signals. Thesignals output by the event detecting devices may include achange-detected time, change-detected positional information of pixels,and the like. As the fields to which event detection sensors may beapplied are increasing, various studies are being undertaken intoimproving the performance thereof.

SUMMARY

Some embodiments of the inventive concepts may provide event detectingdevices including an improved data processing speed and effectivecompensation for an errors occurring in pixels due to external noise orthe like.

According to some embodiments of the inventive concepts, event detectingdevices are provided. An event detecting device may include an eventsignal generator configured to output a plurality of event signals. Eachof the event signals may include a first data and a second data havingmutually complementary attributes, and respective address dataindicating positions of pixels having output the first data and thesecond data. The event detecting device may include a data managerconfigured to store one of the first data and the second data of a firstone of the plurality of event signals and the respective address data ina buffer as first sub data when only the one of the first data and thesecond data of the first one of the plurality of event signals includesevent information, and to store one of the first data and the seconddata of a second one of the plurality of event signals and therespective address data in the buffer as second sub data when only theone of the first data and the second data of the second one of theplurality of event signals includes event information. The eventdetecting device may include an output signal generator configured togenerate an output signal using the first sub data and the second subdata when the second sub data is stored in the buffer.

According to some embodiments of the inventive concepts, event detectingdevices are provided. An event detecting device may include a pixelarray including a plurality of pixels arranged in a plurality of rowsand a plurality of columns. The event detecting device may include anevent signal generator configured to generate an event signal, bygrouping pixel signals output by two or more adjacent pixels among theplurality of pixels into a group. The event signal may include a firstdata and a second data generated from the pixel signals and havingcomplementary attributes. The event detecting device may include anoutput signal generator configured to combine at least a first portionof the event signal with at least a second portion of another eventsignal when only one of the first data and the second data of the eventsignal includes event information, and to provide the combination as anoutput signal.

According to some embodiments of the inventive concepts, event detectingdevices are provided. An event detecting device may include a pixelarray including a plurality of pixels. The event detecting device mayinclude an event signal generator configured to classify the pluralityof pixels into a plurality of groups, and to generate a plurality ofevent signals, based on position information of the pixels included inrespective ones of the plurality of groups, and polarities of pixelsignals output from the pixels included in the respective ones of theplurality of groups. The event detecting device may include an outputsignal generator configured to generate an output signal by combining afirst event signal corresponding to a first one of the plurality ofgroups with a second event signal corresponding to a second one of theplurality of groups when polarities of each of the pixel signalsgenerated, by the pixels of the first one of the plurality of groups areequal to each other, and to output the output signal.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the inventive concepts will be more clearly understood inview of the detailed description and the accompanying drawings.

FIG. 1 is a block diagram illustrating an event detecting deviceaccording to some embodiments of the inventive concepts.

FIG. 2 is a block diagram illustrating a pixel array included in areevent detecting device according to some embodiments of the inventiveconcepts.

FIG. 3 is a circuit diagram illustrating a pixel circuit included in anevent detecting device according to some embodiments of the inventiveconcepts.

FIGS. 4 and 5 are block diagrams illustrating event signals generated inan event detecting device according to some embodiments of the inventiveconcepts.

FIG. 6 is a block diagram illustrating an event detecting deviceaccording to some embodiments of the inventive concepts.

FIG. 7 is a block diagram illustrating an output signal generated by anevent detecting device according to some embodiments of the inventiveconcepts.

FIG. 8 is a flowchart illustrating operations of an event detectingdevice according to some embodiments of the inventive concepts.

FIG. 9 is a block diagram illustrating an electronic device including anevent detecting device according to some embodiments of the inventiveconcepts.

DETAILED DESCRIPTION

Some embodiments of the inventive concepts will be described withreference to the accompanying drawings. Like reference numerals in thedrawings may denote like elements, and thus repeated descriptions may beomitted for brevity.

FIG. 1 is a block diagram illustrating an event detecting deviceaccording to some embodiments of the inventive concepts.

Referring to FIG. 1, an event detecting device 10 according to someembodiments may include a pixel array 20 and, a processor 30. The pixelarray 20 may generate art electrical signal by sensing an increase ordecrease in light, and may include a plurality of pixels arranged in aplurality of rows and columns.

The processor 30 may include a scan module 31, an event module 32, aninterface 33, a control logic 34, and the like. The scan module 31 mayscan the pixels included in the pixel array 20 in a direction of one ofa plurality of rows and columns. For example, the scan module 31 mayscan horizontally or vertically. In some embodiments, the scan module 31may sequentially scan a plurality of column lines.

The event module 32 may generate an output signal including an eventdetection result, using an electric signal output front the pixelsconnected to the column lines scanned by the scan module 31. In someembodiments, the event module 32 may generate an event signal includinginformation, regarding a polarity based on an increase or decrease inlight, a position of a pixel in which an increase or decrease in lighthas occurred, a time at which an increase or decrease in light hasoccurred, and the like, using one or more pixel signals output by thepixels.

The interface 33 may communicate with external devices. In someembodiments, the interface 33 may exchange data with an applicationprocessor or the like according to a mobile industry processor interface(MIDI) protocol. The control logic 34 may control operations of the scanmodule 31, the event module 32, and/or the interface 33.

The event signal may include a first data and a second data havingcomplementary properties and indicating polarities of events generatedin respective pixels, address data indicating a location of a pixel inwhich an event occurs, and the like. In some embodiments, for example,when both the first data and the second data include event information,the processor 30 may transmit an event signal to the interface 33 as itis. On the other hand, when only one of the first data and the seconddata includes event information, the processor 30 may temporarily storethe event information in a buffer, and may combine the event informationwith event information included in event signals generated thereafter,to output an output signal. For example, when an event signal isgenerated by pixel signals having one polarity, the event signal may becombined with another event signal generated later, and then, may outputthe combined signal as an output signal. Thus, a data processing speedmay be increased, and a transmission amount of an output signal may bereduced.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. Thus, a first element could be termed a secondelement without departing from the teachings of the present inventiveconcepts.

FIG. 2 is a block diagram illustrating a pixel array included in anevent detecting device according to some embodiments of the inventiveconcepts.

Referring to FIG. 2, the pixel array 20 according to some embodimentsmay include a plurality of pixels PX arranged in a plurality of rowlines ROW and column lines COL. In some embodiments, the pixel array 20may include N row lines ROW and M column lines COL. Thus, the pixelarray 20 may include a total of M×N pixels PX.

The plurality of pixels PX included in the pixel array 20 may be scannedin a row line (ROW) or column line (COL) unit. In some embodiments, apixel signal may be detected from the pixels PX while sequentiallyscanning the plurality of column lines COL, and an event signal may begenerated using the pixel signal. The event signal may includeinformation, such as a type of an event corresponding to an increase ora decrease in light, a position of a pixel in which an event hasoccurred, a timestamp value corresponding to an event occurrence time,and the like.

FIG. 3 is a circuit diagram illustrating a pixel circuit included in anevent detecting device according to some embodiments of the inventiveconcepts.

Referring to FIG. 3, a pixel circuit 100 of an event detecting deviceaccording to some embodiments may correspond to a pixel PX of the pixelarray 20. The pixel circuit 100 may include a first circuit 110 and asecond circuit 120. In some embodiments, the first circuit 110 mayconvert a charge generated in a photodiode PD provided for each pixel,into a first voltage V_(PR), and may output the converted voltage.

For example, when a charge is generated in the photodiode PD accordingto a change in light, a first amplifier AMP1 may amplify a voltageV_(PD) based on the charge of the photodiode PD. As an example, thefirst amplifier AMP1 may amplify the voltage V_(PD) of the photodiode PDby a logarithmic scale, and thus, a magnitude of the first voltageV_(PR) may be linearly proportional to an intensity of light sensed bythe photodiode PD.

The second circuit 120 may generate a pixel voltage V_(PX) indicating anamount of change in light using the first voltage V_(PR). The secondcircuit 120 may include a first capacitor C1, a second capacitor C2, aswitch SW, and a second amplifier AMP2.

The first capacitor C1 may be connected between an output terminal ofthe first amplifier AMP1 and an input terminal of the second amplifierAMP2, and may be charged with a charge depending on a change in thefirst voltage V_(PR). The second amplifier AMP2 may generate the pixelvoltage V_(PX) by amplifying a voltage of the first capacitor C1according to a ratio of capacitance values of the first capacitor C1 andthe second capacitor C2. The switch SW may reset the charge charged inthe first capacitor C1.

In some embodiments, the pixel circuit may include one or more circuitsdifferent from the first circuit 110 and second circuit 120 of FIG. 3 inorder to measure an amount of change in light and/or to generate thepixel voltage V_(PX) indicating the amount of change in light.

The event detecting device according to some embodiments may generate anevent signal using the pixel voltage V_(PX). In an example, the eventsignal may include information, regarding a position of a pixel havingoutput the pixel voltage V_(PX) corresponding to an increase or decreasein light, time at which the pixel has output the pixel voltage V_(PX),and a type of art event corresponding to an increase or decrease inlight estimated from the pixel voltage V_(PX), and the like.

The event signal may be encoded in a predetermined format, and in someembodiments, the event signal may include a first data and a second datahaving complementary properties to each other. For example, an eventsignal may be output including both a first data and a second dataregardless of event information included in each of the first data andthe second data. Accordingly, when the event information is onlyincluded in the first data, since both the first data and the seconddata are output, an amount of transmission of data may be unnecessarilyincreased.

Thus, according to some embodiments of the inventive concepts, forexample, when only one of the first data and the second data has eventinformation using complementary attributes of the first data and thesecond data, event information may be combined with event information ofanother event signal to be output. Thus, a transmission amount of anoutput signal may be reduced, and a data processing speed may beincreased.

FIGS. 4 and 5 are block diagrams illustrating event signals generated inan event detecting device according to some embodiments of the inventiveconcepts.

In an event detecting device according to some embodiments, two or morepixels, adjacent to each other, may be defined as one pixel group, anddata generated in pixels included in each pixel group may be output in asingle data format. For example, when a pixel array of the eventdetecting device includes M column lines and includes N row lines, eventsignals may be output in an order in which the M column lines arescanned. In addition, a group of pixels may be defined by groupingadjacent pixels among N pixels connected to each of the M column lines,for example, grouping adjacent portions of the N pixels connected toeach of the M column lines. The number of pixels included in each of thepixel groups may be a divisor of N. As an example, when the number ofpixels connected to each of the M column lines is 480, the pixel groupmay include four or eight pixels connected to a single column line andadjacent to one another.

On the other hand, in some embodiments, event signals generated by theevent detecting device may be output in the order of scanning the Mcolumn lines. Referring to FIG. 4, an event signal may include columnaddress data Col Addr indicating a position of a column line, and eventdata generated by pixels connected to each of the column lines.

Respective event data may include a first data Data1 and a second dataData2 having mutually complementary attributes. The first data Data1 andthe second data Data2 may each have a plurality of bits, and the numberor bits included in each of the first data Data1 and the second dataData2 may be the same as the number of pixels included in one pixelgroup. For example, when the pixel group is connected to one columnregion and includes four pixels adjacent to one another, each of thefirst data Data1 and the second data Data2 may have four bits. On theother hand, for example, when the pixel group is connected to one columnregion and includes eight pixels adjacent to one another, each of thefirst data Data1 and the second data Data2 may have eight bits.

Each of the event data may include group address data Group Addrindicating a position of a pixel group having output the first dataData1 and the second data Data2. It may be determined in which positionof a pixel array the first data Data1 and the second data Data2 haverespectively been generated, using the group address data Group Addr,and column address data Col Addr included in the event signal.

For example, a pixel array may include pixels arranged in a 640×480array, and one pixel group may include four pixels adjacent to oneanother on a column line. In this case, when the column address data ColAddr is 0 and the group address data Group Addr is also 0, four bitsincluded in each of the first data Data1 and the second data Data2 maybe determined as having been generated from pixels positioned atcoordinates (0,0), (0,1), (0,2) and (0,3).

FIG. 5 illustrates event signals generated from 480 pixels connected toone column line. In FIG. 5, the 480 pixels in one column line may bedivided into 120 pixel groups. For example, one pixel group may includefour pixels adjacent to each other.

A first event signal 200 may correspond to a first pixel group Group(0),and may include a first data 201, a second data 202, and a group addressdata 203. The first data 201 and the second data 202 may have mutuallycomplementary properties, and may correspond to data respectivelygenerated from first to fourth pixels among the 480 pixels. The groupaddress data 203 may indicate a pixel group having generated the firstevent signal 200, and may have a value indicating the first pixel groupGroup(0).

A second event signal 210, and a third event signal 220 to a 120th eventsignal 230, may also be generated in the same manner as the first eventsignal 200. In FIG. 5, since group address data 203, 213, 223 and 233may have values ranging from 0 to 119, the group address data 203, 213,223 and 233 may include at least seven bits.

Referring to FIG. 5, both the first data 201 and the second data 202included in the first event signal 200 may include event information,while in die second event signal 210 and the third event signal 220,only a second data 212 and 222 may include event information. In the120th event signal 230, only the first data 231 may include eventinformation. Thus, if the second event signal 210, the third eventsignal 220, and the 120th event signal 230 are transmitted to anapplication processor or the like as it is, waste of data transferamount may occur, and unnecessary power consumption may be increased.

When there is a lot of movement of an object that is in view of thepixel array 20 of the event detecting device 10, a probability that onlyone of the first data 201, 211, 221 or 231 and the second data 202, 212,222 or 232 may include event information may be high. In someembodiments of the inventive concepts, for example, when only one of thefirst data 201, 211, 221 or 231 and the second data 202, 212, 222 or 232includes event information by analyzing the event signals 200, 210, 220and 230, relevant event information may be combined with another eventinformation to be output as one output signal. For example, in FIG. 5,pieces of event information included in the second event signal 210 andthe third event signal 220 may be combined into one output signal, andmay be transmitted to an application processor or the like. The outputsignal may include the second data 212 of the second event signal 210,the second data 222 of the third event signal 220, and pieces of groupaddress data 213 and 223 of the respective second and third eventsignals 210 and 220. Thus, the data transfer amount may be efficientlyoperated, and further, power consumption of the event detecting devicemay be reduced.

FIG. 6 is a block diagram illustrating an event detecting deviceaccording to some embodiments of the inventive concepts.

With reference to FIG. 6, an event detecting device 300 according tosome embodiments may include a pixel array 310, an event signalgenerator 320, a data manager 330, a buffer 340, an output signalgenerator 350, an interface 360, and the like. The pixel array 310 ofthe event detecting device 300 may be similar to the pixel array 20 ofthe event detecting device 10. For example, the pixel array 310 mayinclude a plurality of pixels arranged in a plurality of row lines andcolumn lines, and each pixel may output a pixel signal by sensing anincrease or decrease in light based on movement of an object.

The event signal generator 320 may generate an event signal using pixelsignals output from the pixels. The event signal may include an on eventsignal corresponding to an increase in light sensed by the pixels, andan off-event signal corresponding to a decrease in light sensed by thepixels. In some embodiments, two or more pixels connected to a singlecolumn line and adjacent to each other may be represented by one pixelgroup, and the event signal generator 320 may generate one event signalcorresponding to one pixel group. Thus, one event signal may includedata generated from two or more pixels.

The event signal may include a first data, a second data, address data,and the like. The first data and the second data may be data generatedby sensing an increase or decrease in light by a plurality of pixelsincluded in the pixel group, and may have mutually complementaryproperties. The address data may be data representing a position of thepixel group in which the first data and the second data have beengenerated. The address data may include address information of a columnline to which a pixel group belongs, and information indicating whichnumber, among pixel groups in a relevant column line, the pixel groupis.

The data manager 330 may determine whether only one of the first dataand the second data includes event information or whether both the firstdata and the second data include event information. For example, whenboth the first data and the second data include event information, thedata manager 330 may transmit an event signal to the interface 360 as itis. The interface 360 may transmit the event signal as an output signalto an external application processor or the like.

In some embodiments, the data manager 330 may perform an AND operationto determine whether only one of the first data and the second dataincludes event information and which one between the first data and thesecond data only includes the event information. The data manager 330may perform an AND operation in which n bits, where n is a naturalnumber of 2 or more, included in one of the first data or the seconddata, are used as an input, and may determine whether only one of thefirst data and the second data includes event information by referringto an output thereof.

As an example, when a result of the AND operation using n bits includedin the first data is 1, the data manager 330 may determine that thefirst data includes event information. When the result of the ANDoperation using the n bits included in the second data is 1, the datamanager 330 may determine that the second data includes the eventinformation.

When only one of the first data and the second data includes eventinformation, the data manager 330 may store the event information in thebuffer 340 as first sub data. The buffer 340 may store address datatogether with the event information, as the first sub data.

Then, the data manager 330 may receive subsequent event signals, and maydetermine whether only one of a first data and a second data in each ofthe subsequent event signals includes event information. For example,when only one of the first data and the second data in the subsequentevent signals includes event information, the data manager 330 may storeevent information relevant thereto in the buffer 340 as second sub data.

When the first sub data and the second sub data are stored in the buffer340, the output signal generator 350 may generate an output signal byfetching the first sub data and the second sub data stored in the buffer340. The output signal generator 350 may generate the output signalusing the address data and the event information respectively includedin the first sub data and the second sub data. Thus, the output signalgenerated by the output signal generator 350 may include moreinformation than that included in the event signal output by the eventsignal generator 320. The interface 360 may transmit the output signalgenerated by the output signal generator 350 to an external applicationprocessor or the like. A method of generating an output signal by theevent detecting device 300 will be described in more detail withreference to FIG. 7,

FIG. 7 is a block diagram illustrating an output signal generated by anevent detecting device according to some embodiments of the inventiveconcepts. Referring to FIG. 7, a first event signal 200 may include afirst data 201 and a second data 202, including event informationgenerated by sensing an increase or a decrease in light in pixelsincluded in a pixel group, and group address data 203 indicating aposition of the pixel group. The first data 201 and the second data 202may complementary attributes.

The first data 201 and the second data 202 included in the first eventsignal 200 may both include event information. Thus, the data manager330 may transmit the first event signal 200 to the interface 360 as itis, and the interface 360 may output the first event signal 200 as anoutput signal.

In a second event signal 210, different from the first event signal 200,only a second data 212 may include event information, and a first data211 may not include event information. The data manager 330 may extractthe second data 212 including the event information and group addressdata 213 of the second event signal 210, from the second event signal210, and may allow the extracted data to be stored as first sub data inthe buffer 340.

In a third event signal 220 output by the event signal generator 320subsequently to the second event signal 210, only a second data 222 mayinclude event information in. The data manager 330 may store the seconddata 222 and a group address data 223 of the third event signal 220 inthe buffer 340 as second sub data.

When the first sub data and the second sub data are stored in the buffer340, the output signal generator 350 may generate an output signal 210Ausing the first sub data and the second sub data. The output signal 210Amay include the group address data 213 and the second data 212 includedin the second event signal 210, and the group address data 223 and thesecond data 222 included in the third event signal 220. Thus, the outputsignal 210A may include more information than included in the eventsignals 200, 210, 220 and 230. On the other hand, in some embodiments,even when the first event signal 200 is output as it is, null datahaving a plurality of bits may be added to the first event signal 200,such that the first event signal 200 may have the same data length asthe output signal 210A.

FIG. 8 is a flowchart illustrating operations of an event detectingdevice according to some embodiments of the inventive concepts.

Referring to FIG. 8, an operation of an event detecting device accordingto some embodiments may begin in operation S10 with receiving pixelsignals output from respective pixels included in a pixel array. A pixelsignal may be an electrical signal generated in each of the pixels inresponse to an increase or decrease in brightness of light caused bymovement of an object.

In an operation S11, the event detecting device may generate an eventsignal using a pixel signal. The event signal may include a first dataand a second data having event information corresponding to an increaseor a decrease in brightness of light, sensed by the pixels, address dataindicating positions of the pixels having output the pixel signal, andthe like. In some embodiments, the event signal may also includetimestamp values corresponding to times at which the pixels have sensedan increase or decrease in brightness of light. The first data and thesecond data may include event information corresponding to an increaseor a decrease in brightness of light sensed by the pixels included inone pixel group.

In an operation S12, the event detecting device may analyze the eventsignal generated in operation S11 to determine whether both the firstdata and the second data include event information. As a result of thedetermination in operation S12, when it is determined that both thefirst data and the second data include event information, the eventdetecting device may, in an operation S15, transmit the event signalhaving been generated in operation S11 to an external processor or thelike, as an output signal.

On the other hand, when it is determined in operation S12 that only oneof the first data and the second data includes event information, theevent detecting device may, in an operation S13, store the eventinformation in a buffer as first sub data. The first sub data mayfurther include address data indicating positions of the pixels havinggenerated the event information, in addition to the event information.

Then, when second sub data is further stored in the buffer, the eventdetecting device may, in an operation S14, generate an output signalusing the first sub data and the second sub data. Similarly to the firstsub data, the second sub data may include address data and eventinformation extracted from an event signal in which only one of thefirst data or the second data includes event information. The outputsignal generated by the event detecting device in operation S14 mayinclude event information generated in different pixel groups, addressdata indicating positions of the different pixel groups, and the like.In the operation S15, the event detecting device may transmit the outputsignal generated in operation S14 to an external processor or the like.

FIG. 9 is a block diagram illustrating an electronic device including anevent detecting device according to some embodiments of the inventiveconcepts.

Referring to FIG. 9, an electronic device 1000 according to someembodiments may include a display 1010, a memory 1020, an eventdetecting device 1030, a port 1040, a processor 1050, and the like.Constituent elements, such as the display 1010, the memory 1020, theevent detecting device 1030, the port 1040, the processor 1050 and thelike, may communicate with each other via a bus 1060. The electronicdevice 1000 may further include a wired/wireless communications device,a power supply device, and the like, in addition to the constituentelements above.

The processor 1050 may perform specific arithmetic operations, commands,tasks, and the like. The processor 1050 may be a central processing unit(CPU), a microprocessor unit (MCU), an application processor (AP), orthe like, and may communicate with constituent elements such as thedisplay 1010, the memory 1020, the event detecting device 1030, the port1040, and the like, via the bus 1060.

The electronic device 1000 may sense an increase or a decrease inbrightness of light due to a user's gesture, movement, or the like, asan event, using the event detecting device 1030. The event detectingdevice 1030 may be provided according to one or more of the embodimentsdescribed above with reference to FIGS. 1 to 8, and the like.

As set forth above, in the case of an event detecting device accordingto some embodiments of the inventive concepts, for example, when onlyone of a first data and a second data having complementary attributes,included in an event signal, includes event information, the eventinformation may be combined with data of other event signals to beprocessed. Thus, a data processing speed may be improved. In addition,an event may be accurately detected by correcting errors due to noise,hot pixels, dead pixels, and the like, using correlation of timestampvalues generated in respective pixels.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concepts belongs.It will be further understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

While example embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. An event detecting device comprising: an eventsignal generator configured to output a first event signal and a secondevent signal, each of the first and second event signals comprising afirst data and a second data having mutually complementary attributesand respective address data indicating positions of pixels having outputthe first data and the second data; a data manager configured to storeone of the first data and the second data of the first event signal andthe respective address data in a buffer as a first sub data when onlythe one of the first data and the second data of the first event signalincludes event information, and to store one of the first data and thesecond data of the second event signal and the respective address datain the buffer as a second sub data when only the one of the first dataand the second data of the second event signal includes eventinformation; and an output signal generator configured to generate anoutput signal comprising a combination of the first sub data and thesecond sub data when the second sub data is stored in the buffer.
 2. Theevent detecting device of claim 1, wherein the output signal comprises afirst address data indicating positions of pixels having output thefirst sub data, and a second address data indicating positions of pixelshaving output the second sub data.
 3. The event detecting device ofclaim 1, wherein each of the first data and the second data comprises nbits, where n is an integer number of 2 or more.
 4. The event detectingdevice of claim 3, wherein the data manager is configured to store thesecond data of the first event signal in the buffer as the first subdata, when the n bits included in the first data of the first eventsignal are all Os.
 5. The event detecting device of claim 4, wherein thedata manager is configured to store the first data of the first eventsignal in the buffer as the first sub data, when the n bits included inthe second data of the first event signal are all Os.
 6. The eventdetecting device of claim 3, wherein the data manager comprises alogical operation circuit configured to perform a logical AND operationof the n bits included in at least one of the first data and the seconddata.
 7. The event detecting device of claim 3, wherein the n bitsincluded in each of the first data and the second data correspond toevents detected by n pixels that are adjacent to each other.
 8. Theevent detecting device of claim 7, wherein the n pixels are arranged ina single direction in a pixel array.
 9. The event detecting device ofclaim 1, wherein the address data of the second sub data indicatespositions of pixels that are different from pixels indicated by theaddress data of the first sub data.
 10. The event detecting device ofclaim 1, further comprising an interface configured to output the outputsignal to a device external to the event detecting device.
 11. The eventdetecting device of claim 10, wherein the data manager is configured totransmit the first event signal to the interface, as the output signal,when the first data and the second data of the first event signal bothinclude event information.
 12. An event detecting device comprising: apixel array including a plurality of pixels arranged in a plurality ofrows and a plurality of columns; an event signal generator configured togenerate a first event signal, by grouping pixel signals output by twoor more adjacent pixels among the plurality of pixels into a group,wherein the first event signal includes a first data and a second datagenerated from the pixel signals and having mutually complementaryattributes; and an output signal generator configured to generate anoutput signal comprising a combination of at least a first portion ofthe first event signal with at least a second portion of a second eventsignal when only one of the first data and the second data of the eventsignal includes event information.
 13. The event detecting device ofclaim 12, wherein the two or more adjacent pixels are arranged in one ofthe plurality of columns.
 14. The event detecting device of claim 12,wherein the first event signal comprises address data indicatingpositions of the two or more adjacent pixels that output the pixelsignals.
 15. The event detecting device of claim 14, wherein the addressdata comprises information indicating the group to which the two or moreadjacent pixels that output the pixel signals belong.
 16. The eventdetecting device of claim 12, wherein the two or more adjacent pixelsare n pixels adjacent to each other, and each of the first data and thesecond data comprises at least n bits, where n is an integer number of 2or more.
 17. The event detecting device of claim 12, wherein the eventsignal has a data length equal to a data length of the output signal.18. An event detecting device comprising: a pixel array including aplurality of pixels; an event signal generator configured to classifythe plurality of pixels into a plurality of groups, and to generate aplurality of event signals, based on position information of theplurality of pixels included in respective ones of the plurality ofgroups, and polarities of pixel signals output from the plurality ofpixels included in the respective ones of the plurality of groups; andan output signal generator configured to generate an output signal bycombining a first event signal corresponding to a first one of theplurality of groups with a second event signal corresponding to a secondone of the plurality of groups when polarities of each of the pixelsignals generated by the plurality of pixels of the first one of theplurality of groups are equal to each other, and to output the outputsignal.
 19. The event detecting device of claim 18, wherein theplurality of pixels are configured to output the pixel signals withpolarities that are determined based on whether an intensity of lightsensed by the respective pixels increase or decrease.
 20. The eventdetecting device of claim 18, wherein each of the plurality of groupscomprises two or more pixels continuously arranged in a single directionin the pixel array.